Selective ringing system for party-line telephones.



F. 'E WINSLOW.

l SELECTIVE RINGING SYSTEM FOR PARTY LINE TELEPHONES.- APPLICATION FILED MAY 2, 1908,

953,082. Patented Mar- 29, 1919.

4 wrrnzsszs mv z-zgu'ron FRED E. 'WINSLQW, F DES MOINES, IOWA.

SELECTIVE RINGING- SYSTEM FOR PARTY-LINE TELEPHGNES.

Specification of Letters Patent.

Patented Mar. 2%, 1910..

Application filed. May 2, 1908. Serial No. 430,456.

i0 all whom it may concern:

Be it known that Finn; E. lVrusnow, a citizen oi the United States, residing at Des llloines, in the county of Folk and State of Iowa, have invented certain new and useful Improvements in 'Elelective Ringing Elysl'ems lor larty-liine Telephones, of which the following is a specification.

T his invention relates to improvements in selective ringing systems for party-line telephones, and it has for its salient object to provide a system in which the selections are accomplished by inc: ns whichobviate marginal conditions, and the mechanism em ploycd is of the simplest cha actor and the instruments are of well-understood and de veloped types, thus insuring system which is at once simple, practical and reliable.

The invention consists in the matters hereinafter described, and more particularly pointed out in. the appended claims.

Figure 1 is a. diagran'unatic' illustration oi a preferred embodiment of the invention; Fig. 52 is a similar view of a. modification.

ln 1 of the drawing, a practical andprelferred embodiment of the system is shown in a manner largely diagramn'iatic; only so much of the telephone apparatus being shown is directly concerned in the present invention.

ll t is wellunderstood that polarized ringers their clappers spring-biased, 2'. 6. held over to one side or the other by means of a spring, can he selectively rung by pulsating current, one for one polarity and another for the opposite polarity. it is also common in the telephone art to use direct current ringers, ic. ringers which will respond battery or other direct current placed to the line and ailording a continuous current flow. It is also known that electromagnetic ringers may be made quick so as to be responsive to current of high frequency, or sluggish and responsive only to current periods or relatively long duration; both the mechanical construction and the character of the winding of the magnets being utilizable factors for securing these results.

Utilizing the foregoing facts and principles, l have devised. the selective system herein described, in which I so organize the system that two biased ringers, one for each polarity, are rung from each main line or limb of the circuit, and one direct current ringer operated from each main line or linih, thus ailording six different selections.

Referring to the diagram, L and R, re

spectively, designate the two main limbs of as connected in the usual bridging relationto the main limbs.

7, 8 and 9 designate three switclukeys at the exchange, and 10, 11 and 12 generators corresponding to the respective keys. Two of these generators, as for example 10 and 11, are so organized as to all'ord pulsating current of relatively high frequency and of dilierent polarity, the generator 10 being shown in the diagram as affording positive current pulsations, and the generator 11 negative current. The generator 12 allords direct or continuous current. All of the generators are grounded at one side through their respective brushes and the common grounding line 13, extending to ground Each of the substations having a biased ringer, is provided with a controlling relay 15, which controls a. corresponding interrupted grounding branch, as 16, extending through the ringer 17 of its station to ground at 18. The controlling relay of each station is ei'icrgizcd through a bridge connection, as 19, which includes the windings of the relay, and includes also a condenser 20, and these controlling relays are wound high and closely adjusted so as to be extremely quick and sensitive. I

It will be noted that the bridge connections of the several controlling relays all connect at one side with the leftfliue L, and at the other side with the right line R, and

so I

further that each of the two main limbs is The two direct current ringers are so 01' ganizcd as to be sluggish. in their movements and not responsive to that frequency or pulsations afforded by the two generators l0 and 11. Said ringers are of the self-interrupting type, their armaturcs 25 being arranged to close with short 'circuiting contacts 26, as shown clearly in the diagram. in order to minimize loss of current by flow to ground through one or the other of these direct current ringers which are permanently connected to ground, the ringers are either wound relatively high or maintained in series with resistance coils as indicated at 27; the resistances shown licing inductive so that the ncc may aid in pseventfii th s direct e reni, ringers from res 'iondiu to the pulsating Ctll")lll..

new that lacy i' he i'iscillated orresponding contacts 28,

and a ci i: W ablishc lthrough rho positive i iei t main line and through l controlli relays 11.5 in opposite main line and to no direct current ringer lling relays will d so c.v ahlisli closed ciris sei 'orai branches l6 lead- :iive ringr The ringer at because thc polarity the right direction. I will not be rung hethe .i'rong polarity. ens and 4 will not be r to u can receive only such curnopulscs as reach the right main passing through the primary wind and i h relay windings oi the several r-n i'nat the ringing branches of two stations effectually shunt and u. operation of the rucoecdin two stacisely the manner when .t in the opposite diiaiction, from generator will to placed on the right main line through the 3.8 and 2 and this will result in operating the ringer at station 3 (after the controlling rota": have operated), while the ringers at. the first two stations will not he opcraiied because the conditions will be exactly 1 versed as compared with the condition first described. In precisely the same manner key S will ring either of the two negative. biased ringersat stations 2 and -it, depending upon which direction the key 8 is oscillated. "When key 9 is "operated in one direction, as for example so to close circuit netwcen contacts :28 and 29. direct current will flow from ground at let through the generator 12, over the left main line to and tlu'onglrtlie direct current ringer at station 5. This ringer being self-interranting, it will continue to ring as long as current is maintained on the line. in proy the same manner the ringer at staiio t isoperaied hy moving key 9 so as to close contact between "28 and 29.

As hereinhe'torc noted the two direct ourrent; rin are. made siugg'sh, so that they do not; 2. "Kind to the high frequency short pulsations thrown. to line from the generators l0 and 11. It is, of course, apparent that the biased ringers will not vibrate under the action of direct continuous current. it is also to he noted that the several conliolling relays 25, white they will be closed momentarily when the direct current i placed on the line, will. nevertheless promptly return to open position, owing to the roinlcnscrs interposed in their several bridges, so that the direct current ringers will receive the full cli'cct of the current sent; to line.

In 2 I have shown a modification in which the controlling relays are omitted and the pulsating current ringers arranged in pcrn'umently grounded branches 30. In his illustration the two ringers are shown being both biased to respond to current of one polarity but as connected to different;- sides or the main line. it will be obvious that when the proper key is closed to send era-rent over the left main line, the first rin 'e-r 31 will be. operated, but no current wil reach the ringer of the other station 32 hccause the right main line is entirely disconnected from the left at this station. Vice Ycrsa when current is placed on the right main line the ringer 32 will be 0pcrated but the other will. not, for the same reason. The purpose of the controlling relays 15 shown in the first diagram is to normally maintain the grounded branches at their stations open and thus prevent loss of current flow to ground in those systems where the battery is maintained on the line continuously. It is true that there will be a slight loss due to the current flow to ground atone or the other of the direct current ringers, depending upon which line is kept to battery but this loss will be slight because the direct-current ringers are purposely wound high or included in series with high resistances to minimize this current loss.

From the foregoing it will be seen that the system is practically free from marginal conditions; that the circuits are so arranged that the several ringers are not sensitive to unbalanced conditions or resistances in the line, and that this system of selective ringing may be adopted in connection with any ordinary bridging system.

i claim as my invention:

1. In a selective ringing system, the combination with a pair of main wires forming a metallic.telephone circuit extending from an exchange station through a plurality of sub-stations, of means for supplying both direct current and high frequency pulsating current of either polarity to said main lines, a direct continuous current ringer connected with each of said main lines ingrounded branches at different sub-stations, two pairs of pulsating current ringers connected to said main lines at ditferent sub-stations, each pair of said latter ringers being re sponsive to current of different; polarity, and means for ringing either member ofeach pair independently of the other.

2. In a selective ringing system, the combination with an exchange and a plurality of sub-stations, of a pair of line wires con-- nected to the various sub-stations, means for supplying both direct current and pulsating current ol either polarity to said line wires, :1 direct continuous current I'll get connected with each of said main lines in grounded branches at ditl'erent sub-stations, tour pulsating current ringers connected to said main line at: diti'erent sub-stations. one pair of said pulsating current ringers being responsive to current or one polarity. and the other pair responsive to current of opposite polarity. and means for shunting'out' either member of each pair in order to independently ring the other member ol said pair.

3. in a selective ringing system, the combination with a main line circuit extending' from an exchange station through a plurality ot' substations. means for supplying both direct contimious and pulsating cur rent to said line. a direct continuous current ringer included in a grounded branch connected to the main line at. one sub-station, a pulsating current ringer included in a grounded branch connected to the main line at coil interposed in the grounded branch which includes the direct current ringer.

t. in a selective ringing system, the combination with a main line circuit extending from an e.\'change station through a plurality otf sub-stations, means for supplying both pulsating tangent of either polarity and direct continuous current to said main line a direct continuous current ringer in chided in a grounded branch circuit connected with the main line at one sub-station, an impedance coil included in said grounded branch. pulsating current ringers responsive to current ol opposite polarity and each included in a grounded branch connected to said main line at diti'ercnt sub-stations.

.3. In a selcctire ringing system. the coinliinalion with a line circuit extending from an exchange station through a plurality of sub stations and means for supplying direct continuous and intermittent current to the line at the exchange. of a direct continuous current ringer connected to the line at one substation. an intermittent current ringer connected'to the line at another sub-station. a condenser interposed in the branch line which leads through the intermittent cui= rent ringer. and an impedance device asso ciated with the branch circuit which extends through the direct current ringer.

(3. In a selective ringing system. the. com bination with a pair of main wires forming a metallic telephone circuit extending from an exchange station through a plurality of sulwtations, of means For supplying both another sub-station, and an impedance l l l direct continuous current and high frequency pulsating current of either polarity to said main lines, a direct continuous current ringer connected with each of said main lines at different sub-stations, a bridging wire connecting said main lines at four different sub-stations, a pulsating current ringer connected to each of said bridging wires at said four sub-stations, one pair oi said pulsating current ringers being responsive to current of one polarity and the other pair responsive to current of opposite polarity, and m urns tor ringing either meniher of each pair independently of the other.

7. In a selective ringing system, the combination with an exchange and a plurality of sub-stations, o at pair of line wires c0nnected to the various sub-stations, means for supplying both direct continuous current and pulsating current of either polarity to said line \\'ires, a direct continiums current ringer connected with each of said main, lilies in grounded branches at ditt'crent sub stations. a bridging branch wire connecting said main lines at each sub-station, tour pulsating current ringers each connected to'zsaid bridging branch wire at. difierent sub-stations, one pair of said pulsating current ringers being responsive to current of one polarity, and the other responsive to current of opposite polarity and means for shunting out either member of each pair in order to independently ring the other nicmber o't said pair.

8. In a selective ringing system, the combination with aniexcnange and a plurality ot substations. ot a pair of line wires connected to the various sulrstations. means for supplying both direct continuous currentand pulsating current? of either polarity to said line wires. a direct continuous current; ringer connected with each of said main lines at diti'erent sub-stations. bridging wires connecting said main lines at each sub-stalion, four pulsating current ringers connected to said bridging wires at the differentsub-stations, one pair of said pulsating can rent ringers being responsive to current; of one polarity. and the other ringer responsive to current-of opposite polarity and means for shunting out either n'tember of each pair in order to independently ring the other member of each pair comprising a relay and a condenser interposed in each of said bridging wires.

. FRED E. VVINSLOVV. \Vitncsses Auniu'r H. GRAVES, Emmi: Rose. 

